fix(k1): settle same-process standby checkpoint

src/k1link/device_plugins/xgrids_k1/active_acquisition_recovery_checkpoint.py

@@ -2627,6 +2627,7 @@ def _require_gap_cessation_evidence_session(
     failed_binding: ActiveAcquisitionRecoveryTransportBinding,
     failed_evidence_session_id: str,
     status_proof: ActiveAcquisitionRecoveryStatusProof,
+    allow_same_runtime_successor_evidence: bool = False,
 ) -> None:
     crosses_runtime_instance = (
         status_proof.binding.runtime_instance_id
@@ -2640,7 +2641,11 @@ def _require_gap_cessation_evidence_session(
             "terminal recovery across a runtime instance requires a successor "
             "evidence session"
         )
-    if not crosses_runtime_instance and not preserves_evidence_session:
+    if (
+        not crosses_runtime_instance
+        and not preserves_evidence_session
+        and not allow_same_runtime_successor_evidence
+    ):
         raise ActiveAcquisitionRecoveryCheckpointTransitionError(
             "same-runtime terminal recovery must preserve the exact evidence session"
         )
@@ -3316,16 +3321,26 @@ def _require_active_reconciled_standby_shape(
         raise ActiveAcquisitionRecoveryCheckpointTransitionError(
             "restart standby physical proof must advance the active lineage"
         )
+    recovery_binding = cessation_status_proof.binding
+    same_runtime = (
+        recovery_binding.runtime_instance_id == failed_binding.runtime_instance_id
+    )
     if (
-        cessation_status_proof.binding.runtime_instance_id
-        == failed_binding.runtime_instance_id
-        or cessation_status_proof.binding.control_session_id
-        == failed_binding.control_session_id
+        recovery_binding.control_session_id == failed_binding.control_session_id
         or cessation_status_proof.evidence_session_id
         == failed_evidence_session_id
+        or (
+            same_runtime
+            and (
+                recovery_binding.host_path_epoch == failed_binding.host_path_epoch
+                or recovery_binding.producer_generation
+                == failed_binding.producer_generation
+            )
+        )
     ):
         raise ActiveAcquisitionRecoveryCheckpointTransitionError(
-            "restart standby settlement requires new runtime, control and evidence sessions"
+            "standby settlement requires a new control/evidence boundary; "
+            "same-runtime recovery also requires a new host path and producer generation"
         )
 
     gap_started = _validated_timestamp(
@@ -4982,6 +4997,9 @@ def _validate_checkpoint_semantics(
                     prior_active_status.evidence_session_id
                 ),
                 status_proof=status,
+                allow_same_runtime_successor_evidence=(
+                    receipts[-1].kind == "cease-active-reconciled-standby"
+                ),
             )
         if receipts[-1].kind == "cease-active-reconciled-standby":
             gap_started_at_utc = checkpoint.last_gap_started_at_utc